JPH117893A - Gas discharge display panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance the contrast of a display screen and improve the display quality in the larger size and higher precision of a display panel by controlling the discharge interference to an adjacent discharge cell by the extension of discharge in each discharge cell, reducing the resistance of a discharge electrode having small irregularities on a substrate surface, and reducing the light reflectance of a discharge electrode. SOLUTION: This panel comprises a plurality of discharge electrode pairs 33 consisting of transparent electrodes 36a, 36b and metal bus electrodes 35a, 35b, respectively, which are arranged adjacently on the inner surface of a display surface-side glass substrate 11, and the discharge electrode pairs 33 are covered with a dielectric layer 13. A strip protruding part 32 lower than the thickness of the dielectric layer 13 and recessed parts 31a, 31b for burying the discharge electrode pairs 33 are provided integrally with the glass base 11 between the respective discharge electrode pairs 33, the metal bus electrodes 35a, 35b are buried in the recessed parts 31a, 31b, and the transparent electrodes 36a, 36b are laminated on these electrodes, respectively, whereby the discharge electrode pairs 33 are arranged.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a gas discharge display panel used for a display terminal or a display device of a computer.

2. Description of the Related Art Plasma display panels (PDPs), which are known as gas discharge display panels, are generally widely used as display means for OA equipment because of their excellent display brightness and contrast. It has attracted attention as a thin full-color flat panel display that can display television and can be easily enlarged. Therefore, there is a demand for the flat panel to realize a screen with higher definition, higher contrast, and higher clear display quality.

[0003]

2. Description of the Related Art As a conventional gas discharge display panel of, for example, an AC drive type, a basic structure of a surface discharge type plasma display panel (PDP) for color display is shown in FIG.
As shown in an exploded perspective view of the main part of FIG. 1, a unit electrode area EU of a matrix display has a three-electrode structure in which a pair of discharge electrodes (display electrodes) 12 composed of a pair of X and Y and an address electrode A face each other.

A discharge electrode pair 12 composed of X and Y for surface discharge forming the display line is provided on the glass substrate 11 on the display surface H side with respect to the discharge space 24, and shields display light. In order to minimize the nesa film and ITO (Indium Tin
An Oxide) film is formed by laminating a transparent electrode 12a made of a transparent conductive film such as a film and a metal bus electrode 12b made of a metal film for supplementing the conductivity (lowering resistance).

The discharge electrode pair 12 is covered with a dielectric layer 13 for AC driving for maintaining a gas discharge using wall charges in an insulating state with respect to the discharge space 24. On the surface of 13, a protective film 14 made of a MgO film having a thickness of about several thousand degrees is further provided.

On the other hand, the address electrodes A for selectively emitting light in the unit light emitting region EU are arranged on the glass substrate 21 on the rear side at a constant pitch so as to be orthogonal to the discharge electrode pair 12 composed of X and Y. Are arranged, and 1 is located between each address electrode A.
Stripe-shaped partition walls 22 having a height of about 00 to 150 μm 22
The discharge space 24 is thereby divided in the line direction (the length direction of the discharge electrode pair 12) for each unit light emitting area EU, and the interval between the discharge spaces 24 is defined.

Further, the glass substrate 21 is coated with R (red), G (green), and B (blue) so as to cover the inner surface on the back side including the upper surface of the address electrode A and the side surface of the partition wall 22. A phosphor 23 of three primary colors is provided. In the PDP 1 having such a configuration, the phosphors 23 of each color are excited by ultraviolet rays radiated from the gas discharge in the discharge space 24 at the time of surface discharge to emit light, and a full-color display by a combination of R, G, and B is possible. In the display, the unit light emitting region EU is formed by the partition 22.
Crosstalk between them is prevented.

In the PDP 1 having the above structure, predetermined components are individually provided for each of the glass substrates 11 and 21 as described above, and then the glass substrates 11 and 21 are arranged to face each other and the periphery of the gap is provided. And hermetically sealed to evacuate the interior once and at the same time enclose a discharge gas.

[0009]

By the way, the discharge electrode pair (display electrode) 12 composed of X and Y in the above-mentioned conventional PDP 1 is provided on the surface of the glass substrate 11 with the transparent electrode 12a.
And a chromium (Cr) layer having excellent electrical characteristics and adhesion to the glass substrate 11 and the dielectric layer as a metal bus electrode 12b on the transparent electrode 12a for supplementing the conductivity (reducing the resistance).
Copper (Cu) -chromium (Cr) three-layer metal film, or silver (Ag)
Is formed by a sputtering process or a vacuum deposition process and a photolithography process.

However, with the increase in size and definition of the PDP 1, each discharge electrode pair (display electrode) 12 and address electrode A
The distance between each discharge cell (discharge dot) formed at the intersection with the address electrode A becomes short. In particular, since there is no structure that separates the space between the discharge cells adjacent in the length direction of the address electrode A, the space charge Because the movement makes it difficult to control the discharge,
For example, there arises a problem that a non-selected discharge cell adjacent to a selected and discharged discharge cell is discharged.

On the other hand, since the electrode length of the discharge electrode pair (display electrode) 12 is long and the electrode width is also reduced, the electric resistance of such a discharge electrode pair 12 tends to be large, and a desired value is obtained. To obtain an electrical resistance value, a thick electrode,
In particular, a thick metal bus electrode to be laminated is required for lowering the resistance.

Therefore, it is difficult to form a thin and long discharge electrode pattern, and the thickness of the metal bus electrode 12b increases the unevenness of the substrate surface after the formation of the discharge electrode. If the size of the irregularities on the substrate surface is not more than a certain level of about 10 μm, there is no particular problem in the characteristics of the discharge panel.
When the dielectric layer 13 and the protective film 14 are subsequently formed on the substrate surface, the dielectric layer for the discharge electrode pair 12 having a large step difference from the substrate surface is formed.
There is a problem that the coatability of the protective film 13 and the protective film 14 is deteriorated, and those steps are complicated.

When the thickness of the discharge electrode pair (display electrode) 12 increases, the degree of contact between the dielectric layer 13 and a copper film, for example, of the electrode material exposed on the side of the electrode increases. Also, a problem arises in that bubbles are generated at a contact portion with the electrode material and light transmittance and electric pressure resistance are deteriorated.

Further, apart from such a problem, if a silver (Ag) film or the like having a low electric resistance is used for the metal bus electrode 12b, the metal bus electrode 12b becomes white after the heat treatment, and an external Due to the strong reflection of light from
There was a drawback that display quality deteriorated.

In view of the above-mentioned conventional problems, the present invention electrically separates a space between adjacent discharge cells to prevent discharge interference to adjacent discharge cells due to spread of discharge in each discharge cell (discharge dot). In addition to improving the structure, the arrangement of the discharge electrodes (display electrodes) on the substrate surface is improved to reduce the unevenness of the substrate surface due to the disposed discharge electrodes, and to reduce the resistance of the discharge electrodes and decrease the light reflectance. It is an object of the present invention to provide a novel gas discharge display panel capable of preventing a decrease in luminous efficiency and contrast of a display screen, and realizing an improvement in display quality even for a large-sized and high-definition display panel. Things.

[0016]

According to the present invention, a plurality of discharge electrodes for generating a surface discharge are provided on an inner surface of a pair of substrates disposed opposite to each other with a discharge space therebetween on the display surface side. The pair is a gas discharge display panel which is disposed so as to be covered with a dielectric layer, and between each of the discharge electrode pairs, a strip-shaped convex portion having a thickness smaller than the thickness of the dielectric layer is provided. It is configured to be provided integrally with the substrate.

Each of the discharge electrodes comprises a transparent electrode and a metal bus electrode narrower than the transparent electrode. The metal bus electrode is embedded in a recess formed in the substrate on the display surface side. The metal bus electrode and the surface of the substrate are arranged so as to cover the metal bus electrode and the surface of the substrate.

Furthermore, a dark light-shielding film having a lower reflectance than the metal bus electrode is provided between the inner wall surface of the recess and the metal bus electrode. That is, in the present invention, FIG.
As shown in FIG. 3, a pair of glass substrates 11 on the display surface side of a pair of glass substrates disposed to face each other with a discharge space therebetween is paired with each other, and a plurality of transparent electrodes 36a, 36b and metal bus electrodes 35a, Plural discharge electrode pairs (display electrodes) consisting of 35b
Is covered with the dielectric layer 13 and arranged adjacent to each other between the discharge electrode pairs in the gas discharge display panel, and has a dielectric constant (ε smaller than the dielectric constant (ε = 13.0) of the surrounding dielectric layer 13. = 7.5-8.0) and the projection 32, which is smaller than the thickness of the dielectric layer 13, is provided integrally with the glass substrate 11, so that the intersection between each discharge electrode pair and an address electrode (not shown) is provided. The electric field intensity in the region on each discharge cell (discharge dot) and the region on the convex portion 32 is different, and the spread of the electric field distribution in each discharge cell is suppressed in a direction narrowed as shown by a dashed line. You.

Therefore, as shown in FIG. 1 (b), due to the spread of the electric field distribution indicated by the dashed line generated in each discharge cell in the conventional gas discharge display panel having no projections,
Discharge interference that causes adjacent non-selected discharge cells to be discharged is suppressed, and a good display screen without erroneous discharge can be obtained.

The reason why the projections 32 on the glass substrate 11 have the function of narrowing the spread of the electric field distribution is that the projections 32 having a small dielectric constant ε are located in the immediate vicinity of the adjacent discharge electrode pair. Because.

Further, in the above description, as shown in FIG. 1A, the case where the surface of the dielectric layer 13 provided so as to cover the projection 32 on the glass substrate 11 and the discharge electrode pair is flat. As an example, a bulging portion 37 of about 5 μm is formed only in a region where the flat surface of the dielectric layer 13 is on the convex portion 32 as indicated by a chain line due to a difference in forming material of the dielectric layer 13 and forming conditions. May occur. Although the raised portion 37 has the function of expanding the electric field distribution in the opposite direction, it is located at a position farther than the discharge electrode pair as compared with the convex portion 32, so that the influence is increased.
It is much smaller than 32.

Further, since the height of the raised portion 37 is usually smaller than the height of the convex portion 32, the influence thereof is small. Therefore, even if there is such a raised portion 37, it does not adversely affect the operation of the convex portion 32.

Although description has been made here only from the viewpoint of electric field distribution, this is a description from one main viewpoint, and there are other factors such as the influence of electric charge adhering to the surface of the dielectric layer 13. The effects of these ancillary factors are not described due to their complexity, but the conclusions are the same as described above.

Further, as shown in FIG. 1A, the metal bus electrodes 35a, 35b of the respective discharge electrode pairs are formed on the inner surface of the glass substrate 11.
Depressions 31a, 31b corresponding to the pattern and thickness of 35b are provided integrally with the glass substrate simultaneously with the projections 32, and the depressions 31a,
Metal bus electrodes 35a and 35b are embedded in 31b, and transparent electrodes 36a and 36b are respectively formed on the metal bus electrodes 35a and 35b.
Are stacked to form a discharge electrode pair (display electrode), so that the metal bus electrodes 35a, 35a,
The thickness of 35b can be increased.

Further, metal bus electrodes are provided in the recesses 31a and 31b.
By adopting a configuration in which the metal bus electrodes 35a and 35b are thickened, there is no danger of contact between the electrode material such as a copper film and the dielectric layer 13 on the side surfaces of the metal bus electrodes 35a and 35b. As a result, the problem that bubbles are generated at the contact portion of the dielectric layer 13 with the electrode material and light transmittance and electric pressure resistance are deteriorated is also solved.

Further, metal bus electrodes in the recesses 31a and 31b
By covering the display surfaces 35a and 35b with a dark-color light-shielding film (not shown), reflection of external light is suppressed, and the contrast of the display screen is improved.

[0027]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 2 is a cross-sectional view of an essential part showing one embodiment of the gas discharge display panel of the present invention, and portions having the same functions as those in FIG. 4 are denoted by the same reference numerals.

In this embodiment, as shown in the figure, a pair of discharge electrodes 33 composed of a pair of X discharge electrodes and Y discharge electrodes provided in a stripe pattern
recesses corresponding to the patterns and thicknesses of the metal bus electrodes 35a, 35b narrower than the transparent electrodes 36a, 36b formed together with the transparent electrodes 36a, 36b
10 μm lower than the thickness of a dielectric layer 13 to be described later, which is parallel to both sides of the concave portions 31a and 31b and the concave portions 31a and 31b.
A belt-shaped convex portion 32 having a height of about 30 is provided integrally.

The insides of the recesses 31a and 31b have a lower reflectivity than the metal bus electrodes 35a and 35b constituting the discharge electrode pair 33, for example, chromium (Cr) along the respective inner wall surfaces.
Oxide, Cr-Cu oxide, manganese (Mn) -iron (Fe)-
Dark light-shielding films 34a and 34b made of copper (Cu) -based oxide or the like
Is provided therein, for example, a silver (Ag) film, a copper (Cu) film, or a metal bus electrode 35a made of a chromium (Cr) -copper (Cu) -chromium (Cr) three-layer metal film or the like. 35b is embedded.

The substrate surface between the convex portions 32 arranged in parallel on both sides of the concave portions 31a and 31b is provided with a Nesa (SnO ₂ ) film or an ITO (Indium Tin Oxide) film. The transparent electrodes 36a and 36b made of a transparent conductive film are disposed on the metal bus electrodes 35a and 35b, which are narrower than the transparent electrodes 36a and 36b, to form a discharge electrode pair (display electrode) 33.

Further, on the glass substrate 11 on the display surface side having the discharge electrode pair 33 composed of a pair of X discharge electrodes and Y discharge electrodes having the above-described structure and the projections 32, a dielectric film having a thickness of about several tens μm is provided. The discharge electrode pair (display electrode) 33 is covered with a body layer 13 so as to be insulated from a discharge space.
On the surface of 13, a protective film 14 made of a MgO film having a thickness of about several thousand degrees is further provided.

Then, a phosphor is provided between the glass substrate 11 on the display surface side having such a configuration and each of the address electrodes and the plurality of partitions provided on the address electrodes as described in the conventional example separately. The glass substrate on the back side having the above configuration is overlapped with a predetermined discharge gap therebetween, the periphery of the opposing gap is hermetically sealed, and the inside exhaust gas and discharge gas are sealed to complete the display panel.

In the display panel thus configured, the dielectric constant (ε = 7.5 to 8) smaller than the dielectric constant (ε = 13.0) of the surrounding dielectric layer 13 adjacent to each other between the discharge electrode pairs 33. .
0), and a projection having a height lower than the thickness of the dielectric layer 13
Since the glass substrate 11 is provided integrally with the glass substrate 11, the region on each discharge cell (discharge dot) formed by the intersection of each discharge electrode pair 33 and an address electrode (not shown) and the convex portion
The electric field strength in the region above 32 is different, and the spread of the electric field distribution in each discharge cell is suppressed in a direction to be narrowed, and the space between adjacent discharge cells is electrically separated.

Accordingly, it is possible to suppress discharge interference with adjacent non-selected discharge cells due to the spread of the discharge generated in the selected discharge cell. On the other hand, when the thickness of the metal bus electrodes 35a and 35b is increased in order to reduce the electric resistance value which is increased by making the discharge electrode pair (display electrode) 33 narrower with the higher definition of the display screen, Are formed by deepening the concave portions 31a and 31b by the thickness of the concave portions 31a and 31b.
1b, metal bus electrodes 35a and 35b are embedded, and transparent electrodes 36a and 36b are placed on metal bus electrodes 35a and 35b.
When the discharge electrode pairs 33 are provided by stacking, the unevenness of the substrate surface due to the disposed discharge electrode pairs 33 can be effectively reduced, and the dielectric layer 13
It is easy to form the protective film 14 and the protective film 14 with good coverage.

Further, since there is no contact between the dielectric layer 13 and the metal electrode material such as the copper film on the side surfaces of the thick metal bus electrodes 35a and 35b, as described in the conventional problem to be solved, The problem that bubbles are generated at the contact portion of the body layer 13 with the metal electrode material and light transmittance and electric pressure resistance are deteriorated is also solved.

Further, the display surfaces of the metal bus electrodes 35a and 35b in the recesses 31a and 31b are connected to the dark light-shielding film 34a.
And 34b, even if a silver (Ag) film with a low resistance and a relatively high external light reflectance is used as the metal bus electrode, the reflection of extraneous light is easily suppressed, and the display is performed. The screen contrast is improved over the entire surface, making it easier to see.

Next, a method of manufacturing the gas discharge display panel will be described. FIG. 3 is a sectional view of a main part for sequentially explaining one embodiment of a method for manufacturing a gas discharge display panel of the present invention.

First, as shown in FIG. 3A, a 40% hydrofluoric acid (HF): water (H ₂ O) = 3: 97 etching solution is provided on the surface of the glass substrate 11 on the display surface side. By making full use of a photo-etching process using a transparent electrode, a discharge electrode pair comprising a pair of X discharge electrodes and a Y discharge electrode provided in a stripe shape described later is formed together with a transparent electrode. For example, concave portions 31a and 31b having a depth of several μm to several tens of μm corresponding to the pattern, and the concave portions 31a and 31b
Strip-like protrusions with a height of about 10 μm parallel to both sides of
And 32 are integrally formed.

Next, as shown in FIG.
a and 31b have a lower reflectivity than the metal bus electrodes 35a and 35b constituting the discharge electrode pair 33 by a sputtering method and a photolithography process along the inner wall surface inside the chromium (Cr) oxide film, manganese ( Mn) -Iron (Fe) -Copper (C
In this embodiment, dark-color light-shielding films 34a and 34b made of a chromium oxide (CrO) film having a thickness of 500 to 1000 ° are formed.

Subsequently, a dark light shielding film is formed along the inner wall surface.
Inside the recesses 31a and 31b in which 34a and 34b are formed, a thickness of several μm to several tens μm by a screen printing method and a photo etching process using a metal paste such as Ag, Au, Ni, or a mask plating method. Metal film or a three-layer metal film of chromium (Cr) -copper (Cu) -chromium (Cr) with a thickness of several μm to several tens μm by a sputtering method and a photo-etching process, etc. The electrodes 35a and 35b are formed in a buried state.

Next, as shown in FIG. 3 (c), a sputtering method, a vacuum deposition method, or a screen printing method is applied to the surface of the substrate on which the metal bus electrodes 35a and 35b are buried between the strip-shaped convex portions 32. A tin oxide (SnO ₂ ) film having a thickness of 1000 to 2000 ° or an ITO (Indium Tin Oxid)
e) is formed, and the transparent conductive film is patterned into a stripe shape wider than the metal bus electrodes 35a and 35b by a photolithography process to form a pair of transparent electrodes 36a of X and Y adjacent to each other in parallel. And 36b are formed so as to overlap with the metal bus electrodes 35a and 35b at predetermined intervals, respectively, to form a discharge electrode pair (display electrode) 33.

Subsequently, as shown in FIG. 3 (c), a discharge electrode pair 33 composed of a pair of X discharge electrodes and Y discharge electrodes,
On the glass substrate 11 on the display surface side on which 32 are arranged, an insulating paste such as low-melting glass is uniformly applied by a screen printing method or the like, and dried at a temperature of about 100 to 150 ° C. 50 insulating paste layers made of glass etc.
A firing process is performed at a temperature of about 0 to 600 ° C. to form a dielectric layer 13 made of an insulating film having a thickness of about 10 to 20 μm as shown in FIG.

Thereafter, a protective film 14 of MgO having a thickness of about several thousand m was further formed on the entire surface of the dielectric layer 13 by a sputtering method, a vacuum evaporation method, or the like, so that the irregularities on the substrate surface were reduced. The desired glass substrate 11 on the display surface side can be obtained.

Accordingly, a phosphor is provided between the glass substrate 11 on the display surface side having such a configuration and the address electrodes and the plurality of partitions provided on the address electrodes separately from the conventional example. The glass substrate on the back side of the above is overlapped via a discharge gap formed by the partition wall, the periphery of the opposing gap is hermetically sealed, the inside is once evacuated to a vacuum, and the discharge encloses the panel to form a panel. When completed, the reflection of extraneous light on the metal bus electrodes 35a and 35b is suppressed, and a gas discharge display panel with good display screen contrast is obtained.

The etching method used for patterning the concave portions 31a and 31b, the band-shaped convex portions 32, and the various electrodes on the surface of the glass substrate 11 on the display surface side may be any one of wet etching and dry etching as necessary. These can be selected and used as appropriate.

In the present embodiment, an example is described in which the present invention is applied to a gas discharge display panel intended for a surface discharge type plasma display for color display. It is not limited to the surface discharge type gas discharge display panel, for example, a surface discharge type gas discharge display panel for monochrome display or a discharge electrode (display electrode) having a two-layer structure in which a metal bus electrode and a transparent electrode are laminated. The present invention can be applied to various gas discharge display panels and the like employing the above.

[0047]

As is apparent from the above description, according to the gas discharge display panel of the present invention, the substrate surface on the display surface side on which the discharge electrode (display electrode) composed of the metal bus electrode and the transparent electrode is provided. A concave portion corresponding to the pattern and thickness of the metal bus electrode and a band-shaped convex portion parallel to both sides of the concave portion are provided integrally with the substrate, and the metal bus electrode is embedded in the concave portion. Accordingly, the thickness of the electrode can be increased without protruding from the substrate surface, and as a result, the electric resistance of the discharge electrode (display electrode) can be easily reduced.

Further, by providing a convex portion having a dielectric constant lower than that of the dielectric layer and a height lower than the thickness of the dielectric layer adjacent to each discharge electrode and integrally with the glass substrate, The space between adjacent discharge cells is electrically separated by suppressing the spread of the electric field distribution in the discharge cells formed at the intersections of the discharge electrode pairs and the address electrodes to be narrowed,
Crosstalk and discharge interference can be sufficiently prevented not only on the partition wall on the rear glass substrate side but also on the display surface side.

Further, since the display surface side of the metal bus electrode buried in the concave portion is covered with the dark light-shielding layer, reflection of extraneous light is prevented, and the contrast of the display screen is improved over the entire surface, making it easier to see. Larger display panel,
It is possible to easily obtain a gas discharge display panel having good display quality with respect to high definition, and to achieve a practically excellent effect.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of an essential part for explaining the function and effect of a convex portion and a concave portion of a gas discharge display panel of the present invention.

FIG. 2 is a cross-sectional view of a main part showing one embodiment of the gas discharge display panel of the present invention.

FIG. 3 is a sectional view of a main part for sequentially explaining one embodiment of a method for manufacturing a gas discharge display panel of the present invention.

FIG. 4 is an exploded perspective view of an essential part showing an example of a gas discharge display panel.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Glass substrate 13 Dielectric layer 14 Protective film 31a, 31b Concave part 32 Convex part 33 Discharge electrode pair 34a, 34b Dark light shielding film 35a, 35b Metal bus electrode 36a, 36b Transparent electrode X, Y discharge electrode

Claims (3)

[Claims] 1. A plurality of discharge electrode pairs for generating a surface discharge are disposed on an inner surface of a substrate on a display surface side of a pair of substrates opposed to each other with a discharge space therebetween, covered with a dielectric layer. A gas discharge display panel, wherein a strip-shaped protrusion having a thickness smaller than the thickness of the dielectric layer is provided integrally with the substrate between the discharge electrode pairs. Discharge display panel. 2. Each of the discharge electrodes comprises a transparent electrode and a metal bus electrode narrower than the transparent electrode. The metal bus electrode is embedded in a recess formed in a substrate on a display surface side, and the transparent electrode is The gas discharge display panel according to claim 1, wherein the panel is disposed so as to cover the metal bus electrode and a surface of the substrate. 3. The dark light-shielding film having a lower reflectance than the metal bus electrode is provided between an inner wall surface of the concave portion and the metal bus electrode. Gas discharge display panel.